dtlg (version 0.0.2)

event_count: Count events

Description

event_count() counts events defined by predicate expressions passed in .filters.

Usage

event_count(
  dt,
  patient,
  treat,
  label,
  .filters = NULL,
  .total_dt = dt,
  pct_dec = 1
)

Value

A one-element list, where the element is a data.table.

Arguments

dt

A data.frame containing, at least, the variables indicated in target and treat.

patient

A string indicating the subject identifying variable.

treat

A string indicating the grouping variable, e.g. the variable specifying the treatment population.

label

A string to be used as label in the output reporting table. This should be a text descriptive of the event being counted.

.filters

Predicate expressions identifying events in dt. Argument should be passed as a character vector of expressions to be evaluated in the frame of dt.

.total_dt

Separate table from dt from which to derive total counts per group.

pct_dec

This argument is ignored, and is only kept for backward compatibility reasons.

Examples

# Count deaths per arm.
event_count(
  adsl,
  patient = "USUBJID",
  treat = "ARM",
  label = "Total number of deaths",
  .filters = "DTHFL == 'Y'"
)[[1]]

# Count patients withdraw from study due to an adverse event.
withdrawn_lbl <- "Total number of patients withdrawn from study due to an AE"
event_count(
  adsl,
  patient = "USUBJID",
  treat = "ARM",
  label = withdrawn_lbl,
  .filters = "DCSREAS == 'ADVERSE EVENT'"
)[[1]]

# Count patients with at least one adverse event.
# NB: When `.filters` is `NULL` (i.e., omitted), all records in `dt` are used
# for counting events.
event_count(
  adae,
  patient = "USUBJID",
  treat = "ARM",
  label = "Total number of patients with at least one AE",
  .filters = "ANL01FL == 'Y'",
  .total_dt = adsl
)[[1]]